First record about Porkhov fortress was made in Novgorod's chronicles in 1239. Knight of Novgorod Alexander Jaroslavovitch ('Nevsky') established the trade way along Shelonj river from Novgorod to Pskov by building of small wooden strong points. Porkhov fortress was one of them. Its fortifications consisted two lines of earthen ramparts and ditches and wooden wall above the ramparts.
In 1346 Great Lithuanian knight Olgerd invaded the Novgorod's territory and took by storm fortress Luga and Shelonj and sieged fortress Opocka and Porkhov. Porkhov stood it's first test. Lithuanians got the war indemnity in 300 rubles from the fortress and got away. In 1387 new stone fortress was erected on the right bank of Shelonj river. The fortress had four towers. Towers had 15-17 meters height and 4-6 wooden levels and walls had 1.4-2 meters thick and 7 meters height. The towers pushed out from the wall's line and could flanked the approaches to the walls. All building works were finished within a year.
July 1428 Lithuanian knight Vitovt besieged the fortress. It was the first siege in Russia with mass artillery shelling. The fruitless siege endured 8 days and fortress was badly damaged. In 1430 the big reconstruction was in the fortress. Thick of it's walls was increased considerably up to 4.5 meters at the most dangerous parts. The gates of the fortress were reconstructed too - the portcullis were arranged.
After seizing the Novgorod and Pskov territories by Moscow in 1478 and 1510 the state border was moved to the west far from the fortress. There were not any storms and sieges of Porkhov from this time. It's fortifications lost it's value soon and preserved till nowadays not disturbed by later rebuilding and reconstructions.
The trade city appeared near to the fortress. In 1776 it became the area administrative center. Rapid city growth begun in 1890s after the railway Pskov-Dno was built. The fortress ruined gradually as long as some repair works were held in 1912.
During the WWII Porkhov fell under German occupation for 4 years. Nikolskaya church in the fortress was in action during the war. It's abbot father Pavel was linked with partisans and provided shelter for escapees from German POW camps. February, 1944 German troops burnt the city and gone away.
Now Porkhov is one of the small Russian provincial cities. There few old city buildings preserves. The fortress is restored partly. The wall along river bank is reconstructed and could be observed, but towers are still in the ruined condition without roofs and floors and could be visited only by your own risk. There are the little local museum and nice botanic garden inside of the fortress. Nikolskaya church which was closed in 1930-th is on the duty now.References:
The Mosque–Cathedral of Córdoba, also known as the Great Mosque of Córdoba and the Mezquita is regarded as one of the most accomplished monuments of Moorish architecture.
According to a traditional account, a small Visigoth church, the Catholic Basilica of Saint Vincent of Lérins, originally stood on the site. In 784 Abd al-Rahman I ordered construction of the Great Mosque, which was considerably expanded by later Muslim rulers. The mosque underwent numerous subsequent changes: Abd al-Rahman II ordered a new minaret, while in 961 Al-Hakam II enlarged the building and enriched the Mihrab. The last of such reforms was carried out by Almanzor in 987. It was connected to the Caliph"s palace by a raised walkway, mosques within the palaces being the tradition for previous Islamic rulers – as well as Christian Kings who built their palaces adjacent to churches. The Mezquita reached its current dimensions in 987 with the completion of the outer naves and courtyard.
In 1236, Córdoba was conquered by King Ferdinand III of Castile, and the centre of the mosque was converted into a Catholic cathedral. Alfonso X oversaw the construction of the Villaviciosa Chapel and the Royal Chapel within the mosque. The kings who followed added further Christian features, such as King Henry II rebuilding the chapel in the 14th century. The minaret of the mosque was also converted to the bell tower of the cathedral. It was adorned with Santiago de Compostela"s captured cathedral bells. Following a windstorm in 1589, the former minaret was further reinforced by encasing it within a new structure.
The most significant alteration was the building of a Renaissance cathedral nave in the middle of the expansive structure. The insertion was constructed by permission of Charles V, king of Castile and Aragon. Artisans and architects continued to add to the existing structure until the late 18th century.
The building"s floor plan is seen to be parallel to some of the earliest mosques built from the very beginning of Islam. It had a rectangular prayer hall with aisles arranged perpendicular to the qibla, the direction towards which Muslims pray. The prayer hall was large and flat, with timber ceilings held up by arches of horseshoe-like appearance.
In planning the mosque, the architects incorporated a number of Roman columns with choice capitals. Some of the columns were already in the Gothic structure; others were sent from various regions of Iberia as presents from the governors of provinces. Ivory, jasper, porphyry, gold, silver, copper, and brass were used in the decorations. Marvellous mosaics and azulejos were designed. Later, the immense temple embodied all the styles of Morisco architecture into one composition.
The building is most notable for its arcaded hypostyle hall, with 856 columns of jasper, onyx, marble, granite and porphyry. These were made from pieces of the Roman temple that had occupied the site previously, as well as other Roman buildings, such as the Mérida amphitheatre. The double arches were an innovation, permitting higher ceilings than would otherwise be possible with relatively low columns. The double arches consist of a lower horseshoe arch and an upper semi-circular arch.